Pollen limitation and autonomous selfing ability interact to shape variation in outcrossing rate across a species range.
Pollen limitation and autonomous selfing ability interact to shape variation in outcrossing rate across a species range.
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DOI：
10.1002/ajb2.1342
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发表时间：
2019-08
影响因子：
3
通讯作者：
M. Koski;L. Galloway;Jeremiah W. Busch
中科院分区：
文献类型：
--
作者：
M. Koski;L. Galloway;Jeremiah W. Busch
前提 雌雄同体植物通常通过自交和异交的混合方式繁殖。异交率在多大程度上反映了异交花粉的可用性、自主自花受精能力的遗传分化或两者兼而有之，通常尚不清楚。尽管自主性和授粉环境有可能共同影响异型杂交，但这种相互作用很少被研究。方法 我们回顾了文献中的研究，这些研究测试了授粉环境或导致自主自交的花性状是否可以预测种群间异交率的变化。我们还测量了 23 个美洲风铃种群的异交率，并研究了与授粉环境、自主性及其相互作用的关系。结果我们的审查显示，有利于自交的性状通常与异交率呈负相关，而授粉环境的大多数方面都很难预测异交。美洲锥虫种群的变化范围从混合交配到高度异交，但变异与种群大小、密度、花粉限制或自主自交能力无关。异交率受到自主自交能力和花粉限制之间相互作用的显着影响。在高度自治的种群中，花粉限制的增加与异交减少有关，而对于自治程度较低的种群则没有关系。结论 自我自主能力和花粉限制相互作用，影响美洲美洲锥虫的异交率。这项工作表明，自主性提供了交配系统的灵活性，尽管它并不是在整个物种范围内的所有种群中普遍存在。影响自主性和花粉限制的性状之间的相互作用可能解释开花植物群体之间异交率的变化。
PREMISE Hermaphroditic plants commonly reproduce through a mixture of selfing and outcrossing. The degree to which outcrossing rates reflect the availability of outcross pollen, genetic differentiation in the ability to autonomously self-fertilize, or both is often unclear. Despite the potential for autonomy and the pollination environment to jointly influence outcrossing, this interaction is rarely studied. METHODS We reviewed studies from the literature that tested whether the pollination environment or floral traits that cause autonomous selfing predict variation in outcrossing rate among populations. We also measured outcrossing rates in 23 populations of Campanula americana and examined associations with the pollination environment, autonomy, and their interaction. RESULTS Our review revealed that traits that facilitate selfing were often negatively associated with outcrossing rates whereas most aspects of the pollination environment poorly predicted outcrossing. Populations of C. americana varied from mixed mating to highly outcrossing, but variation was unrelated to population size, density, pollen limitation, or autonomous selfing ability. Outcrossing rate was significantly influenced by an interaction between autonomous selfing ability and pollen limitation. Across highly autonomous populations, elevated pollen limitation was associated with reduced outcrossing, while there was no relationship for less autonomous populations. CONCLUSIONS Both the ability to self autonomously and pollen limitation interact to shape outcrossing rates in C. americana. This work suggests that autonomy affords mating-system flexibility, though it is not ubiquitous in all populations across the species range. Interactions between traits influencing autonomy and pollen limitation are likely to explain variation in outcrossing rates among populations of flowering plants.